Method for manufacturing electrode assembly for electrochemical device, electrode assembly obtained by same method, and method for manufacturing electrochemical device

Abstract

An electrode assembly manufacturing method according to the present disclosure uses a pre-compressed separator substrate. Therefore, a reduction in thickness of the separator by the pressure applied in a lamination process during the manufacture of an electrode assembly is small. For this reason, the separator of the electrode assembly manufactured by the method exhibits high insulation performance and does not experience a decrease in dielectric breakdown voltage. In addition, even though high pressure is applied during the lamination process, damage to the separator is small, and the processing speed is fast, resulting in process efficiency.

1 . A method of manufacturing an electrode assembly for an electrochemical device, the method comprising:
 preparing a porous polymer film member having a porosity in a range of 40 to 70 vol %;   preparing a separator for the electrochemical device by pressing the porous polymer film member to form a porous separator substrate; and   manufacturing the electrode assembly comprising the separator, a cathode, and an anode,   wherein   after the preparing of the separator, a thickness of the porous separator substrate is 90% or less compared to a thickness of the porous polymer film member which is not yet pressed.   
     
     
         2 . The method of  claim 1 , further comprising forming a composite coating layer containing inorganic particles and a binder resin on one side or both sides of the porous separator substrate. 
     
     
         3 . The method of  claim 1 , wherein, after the preparing of the separator, the porous separator substrate has a porosity in a range of 30 to 60 vol %. 
     
     
         4 . The method of  claim 1 , wherein the preparing of the separator is performed using a pressing roller or a pressing jig. 
     
     
         5 . The method of  claim 1 , wherein the preparing of the separator is performed by hot pressing. 
     
     
         6 . The method of  claim 1 , wherein the pressing is performed in a pressure range of 3.0 to 8.0 MPa. 
     
     
         7 . The method of  claim 1 , wherein the porous polymer film member is prepared by a wet manufacturing method in which pores are formed by extracting a pore-forming agent, and
 the porous polymer film member comprises a polyolefin resin.   
     
     
         8 . The method of  claim 1 , wherein the porous polymer film member is prepared by a dry manufacturing method in which pores are formed by melting and extruding a polymer resin and subsequently stretching the extruded polymer resin. 
     
     
         9 . An electrode assembly obtained by the method of  claim 1 ,
 wherein the separator comprises the porous separator substrate.   
     
     
         10 . An electrode assembly obtained by the method of  claim 2 ,
 wherein the separator comprises the porous separator substrate and the composite coating layer on one or both surfaces of the porous separator substrate.   
     
     
         11 . A method of manufacturing an electrochemical device comprising the electrode assembly obtained by the method of  claim 1 , wherein the separator comprises the porous separator substrate. 
     
     
         12 . The method of  claim 11 , wherein the electrode assembly is prepared by disposing and laminating the separator between the cathode and the anode. 
     
     
         13 . A method of manufacturing an electrochemical device comprising the electrode assembly obtained by the method of  claim 2 , wherein the separator comprises the porous separator substrate and the composite coating layer on the one or both surfaces of the porous separator substrate. 
     
     
         14 . An electrochemical device manufactured by the method of  claim 11 . 
     
     
         15 . An electrochemical device manufactured by the method of  claim 13 .